| 摘要 |
PURPOSE:To enable to perform etching generating no damage to a wafer by a method wherein ultraviolet rays of wave length of 380nm or shorter are applied at the same time to an etching material put in a reactive gas atmosphere of Cl2, etc. CONSTITUTION:The etching material of polycrystalline silicon 2 added with phosphorus, for example, on a susceptor 1 is put in the Cl2 gas atmosphere, ultraviolet rays of 240-360nm wave length radiated from a mercury-xenon lamp 4 is focused thereon by a lens 3, and the sample is irradiated. Rays extending from visible rays over rays of long wave length are cut by a filter 8. The absorption peak of Cl2 is in the neighborhood of 330nm wave length, and rays of this wave length effects photodissociation of Cl2 gas with extremely high quantum efficiency. When polycrystalline silicon 10 added with phosphorus, put on a silicon dioxide layer 11 on a silicon substrate 12 and masked with a resist 9 is etched, the silicon is etched isotropically by Cl atoms photodissociated in the vapor phase. |
